↑Treaty of alliance between France and Portugal concluded at Paris, June 1, 1641. Davenport, Frances Gardiner: European Treaties Bearing on the History of the United States and Its Dependencies to 1648. Clark, New Jersey: The Lawbook Exchange, Ltd., 2012. ISBN9781584774228, pp. 324-328
↑Encyclopædia Britannica. “John IV (king of Portugal)”. king of Portugal from 1640 as a result of the national revolution, or restoration, which ended 60 years of Spanish rule.
↑Geoffrey Parker, The army of Flanders and the Spanish road, London, 1972 ISBN0-521-08462-8, p. 35